Modem communication is a widely used for of communications between computers over telephone lines. A local modem is typically connected to a personal computer through a serial interface and the local modem is connected to the telephone line. At a remote location, a remote modem is connected in a similar fashion between the remote end of the telephone line and the remote personal computer.
Modems typically operate in two modes of operation: ON-LINE mode and COMMAND mode. The method often used to switch between modes of operation is the escape sequence. Escape methods primarily exist so that upon completion of a call a modem can be hung up. The process of hanging up a modem can be accomplished in many ways' one of which is to drop the DTR signal, another way is to "escape" or change the modem from ON-LINE mode into COMMAND mode, so that a hang up command can be sent to the modem. Prior art use of escape methods are manifold and are described in the following patents and documents, which are hereby incorporated by reference:
______________________________________ U.S. Pat. No. Inventors Issued ______________________________________ 2,347,831 Kinkead May 2, 1944 2,430,447 Branson et al. November 11, 1947 2,543,174 Keyes et al. February 27, 1951 2,587,483 Keyes et al. February 26, 1952 2,735,885 Keyes et al. February 21, 1956 2,871,286 Bacon et al. January 27, 1959 2,948,777 Andrews et al. August 9, 1960 3,304,372 Filipowsky February 14, 1967 4,208,545 Zener June 17, 1980 4,549,302 Heatherington October 22, 1985 ______________________________________